Latch dampening device



March 4, 1952 G. B. DOREY LATCH DAMPENING DEVICE Filed Nov. 18, 1949 INVENTOR. 40290/ eof March 4, 1952 G. B. DOREY LATCH DAMPENING DEVICE 5 Sheets-Silea?I 2 Filed NOV. 18, 1949 INVENTOR.

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March 4, 1952 G. B. Dom-:Y

LATCH DAMPENING DEVICE Filed Nov. 18, 1949 5 Sheets-Sheet 5 4 INVENTOR.

Patented Mar. 4, 1952 UNITED STATES PATENT oFFlcEi LATCH DAMPENING DEVICE George B. Dorey, Westmount, Quebec, Canada, assignor to Enterprise Railway Equipment Company, Chicago, Ill., a corporation of Illinois Application November 18, 1949, Serial No. 128,209 9 o1a ims.- Y(o1. 10a-sos) This invention relates to a dampening device for a hopper door latch and is more particularly adapted for use with a latch bar pvotally mounted on a door for movement about its axis to engage with a shouldered keeper on the hopper.

An object of this invention is to dampen or cushionthe releasing movement of a latch when violently displaced from its normal position such as occurs when such displacement is made by contact with a striker surface upon movement of a door to closing position. In the type of latch adapted to engage with a shouldered keeper having a beveled striker surface leading thereto and slammed or` kicked to closed position, the latch F bar is thrown away from the striker surface to the limits of its travel and, under certain circumstances, may again contact the striker to re peat the bouncing cycle before the door reaches closed position. It is therefore another object of this invention to control such movement and provide for delayed action in the releasing move'- ment of the latch.

This invention is shown as applied to a hopperV car of the type having a vertically swingable door pvotally mounted adjacent the upper margin 'of a discharge opening. In the drawings: Figure 1 is a view taken transversely of a portion of a hopper type car showing the center sill and side wall in section and a door for closing the discharge hopper opening in elevation, the door being shown in pendant open position;` Figure 2 is a detail sectional view taken genen. ally along the line 2-2 of Figure 1 and showing the door in the closed and latched position; vand Figures 3 and 4 are views, at an enlarged sc ale, showing different operating positions of the latch mechanism and dampening means therefor which are constructed in accordance withV this invention and embodied in the door and hopper construction shown in Figures 1 and 2.

A portion of a hopper type car is shown as including a center sill S and a car side wall I spaced outwardly therefrom.- Interposed between' them is a hopper II having a discharge opening I2. The hopper II is defined in part by a. floor I3 sloping downwardly towards the lower margin of the opening I2 and inner and outer side walls as indicated at I4 and I5 respectively. sloping downwardly towards the upper margin of the opening I2 is a floor I6.` Underlying the oor I6 and overlying the lower sloping floor I3 and side walls I4 and I5 there is a frame shown, generally, at I1 having hinge butts I8 along the upper part thereof. Pivotally mounted on the hinge butts I8 by hinge pins I9 is a door. 20 Which is adapted to be moved to an inclined closed position and be there retained by latching mechanism to be described.

The latching mechanism shown includes a latch bar 2 I pvotally mounted at one end Von a beam member 22 which is in turn securely mounted on the outer face of the door 20. Cooperating with the latch bar 2| at a location intermediate the ends thereof is a shouldered keeper or locking hook 23 which is secured to the hopper oor I3 and extended through an opening 24 formed in the door 20 and door beam member 22.

The keeperor hook 23 is provided with a shoulder 25 which engages with the latch bar 2I for retaining the door 2i) in closed position and leading to this shoulder the keeper or hook 23 is provided with an inclined striker face 26 for engagement with the under side of the latch bar 2I and displacing the same upwardly as the door 2!) is moved towards closed position. The outer end of the latch bai` 2l is retained between the inner surfaces of extensions or arms 2'I formed integrally with and extending upwardly from the beam member 22.

Pivotallv mounted at 28 between the extensions or arms 21 there is a locking cam 29 whichvis adapted to engage in the usual manner for locking the latch bar 2| in closed position. The cam 29 in its released position is movable to an overbalanced position and it has been customary to limit the overbalancing movement a suiicient extent to maintain the cam 29 clear of the latch bar 2I' so that it ca n move tully throughout its entirefrange of movement without interference therefrom.

The present invention contemplates broadly the provision of a weighted retarding element to actA on the latch bar 2| as it approaches its iinal.

lifting stage. In carrying this out this element4 a damper therefor when the cam 29 is moved to an overbalanced released position. In practicing the invention the cam and dampening element 29. is formed with an arcuate surface 30 struck on an arc at a radius 3| extending from a center 3|' spaced horizontally from the pivot axis 28 of the cam 29. A stop 32 is provided on the cam 29 to engage'an edge -33 .of the overlying extension or arm 2``| .to maintain the cam 29 in a denite position of release. The stop 32 holds the combination locking cam and dampening element 29 in a position where its center of gravity is located well to the right of the center 3| of the arcuate surface 30.

The cam 29, when in overbalanced `released position as indicated in Figure 3, lies inthepatn of movement of the latch bar 2| and is positioned to contact the latter While it `is still inlcontact with the upper portion of the striker surface 26 as indicated by the broken line showing of the latch bar 2|. Continued movement of the latch bar 2|1inan upward'direction causes the arcuate surface r30 of the cam 29 to'slide androll along the upper surface 34 of .the latch bar 2|. This causes the cam29 to turn on its pivotal "axis and gradually moves thepoint of 'contact between the cam 29 and the latch'bar 2| until the maximumA displacement of the latch bar 2| is reached when, as shown in Figure 4,'the line of contact between 'surface 34 of the latch bar 2| is at rightangles tothe 'radius 3| which now extends throughthepivot axis 29 of the cam 29. The necessity for overcoming the mechanical inertiav of the cam' and dampening element 29 and therolling and 'sliding contact thus established between it and latch bar 2| has the effect of cushionin'g the upthrow of the latter and provide the equivalent of a'delayed'squeezing motion in contrast to a. Vhammerlike blow.

rExtendimgf, in lopposite directions from the arcuatev surface 30 and tangentially related theretotheup'per surface 34 of thelatc'h bar 2| as Y contact is established between the cam 29 and th'elatchbar2l during'the upward displacement ofthe latter. vThe other'at surface 36 comes into actiony onlyin the event'that the` upthrow ofthe latch'bar 2'I'is of sufficient violence as to 'overbalance the cam 29. VA tendency for the'cam 29 to overbalance or V:turntoo' far in `a counter clockwise direction'isgenerally'associated with `a delayed returnof'thelatch bar 2|. The 'nose 31 at the extremity of the fiat surface 36' then acts asa vhammerV to accelerate vthe downward Ymovement of thel'atchibarV 2| `anda-assures its downward movement into latchin'gengagementwith the-shoulder-'25 on'fthexkeeper or hook 23while thefdoor closing movement Visv still` in progress.

While'I have shown my improvement as incorporatedin the locking cam 219 it will be understood that the same is` shown as a preferredembodiment making for a minimum number of parts and that the. device may be incorporatedin theformof oneor more Separate members. .Jl'Si-nce certain changes .canbe made in the'foregoing .construction and .different vembodiments.of the vinvention canA be made without departing from the spirit andscope thereof, it is intended that all matter s hown in theaccompanying drawings and described hereinbefore shall .be interpreted `as illustrative .andnot in `alrniting sense. {.What:-isciaimedfeasinewdm v v 1 1..','F,.or .combination =wth :a '.'hopper 'Shaving discharge opening, a pvotally mounted door for closing said opening, and a latch bar pivotally mounted on said door to swing parallel thereto and biased to engage a shouldered keeper carried by said hopper, said keeper having an inclined striker surface to be engaged by said latch bar for displacing it upwardly when said door is swung vto closed positionandsaid llatch bar is moved upwardlyfrom a rest position to permit operative engagement between it and said keeper;

. adampening element disposed in the path of upward movement of said latch bar and adapted to :engage-the same and retard such upward move- Ament when itis moved a predetermined distance vaway from said rest position, and stop means for holding `said dampening element in operative position .with .respect to said latch bar so that said dampening element can function as aforesaid.

2. The invention, as set forth in claim 1, wherein the dampening element is engaged by the latch'bar intermediateitsfrest and latched positions and is adaptedto moveconjointly therewith.

3. The invention, as set forth in .claim l, wherein the dampening element isvpivotally mounted on the door tozswing in the plane of the latch'bar.

'4. -Theinvention, as set forth in claim 1, wherein the dampening element is a cam pivotally mounted on the door and is Yadapted in one position to lock the latch bary in latched position and in another position Vto be lengaged by saidlatch bar intermediate its'r'est and latched positions to perform its'retarding function.

'5. The invention, -as .setfforth in claim "1, wherein the dampening element has an arcuate surface for 'engagementby the latch .barintermediate its rest and latched .positions .and

displaced upwardly therewith accompanied by sliding land rolling contact therebetween.

'6. The invention, as set'forth inclaim 5. wherein the dampening element has a nose portion constituting an extension from the arcuate surface generally parallel to the door and adapted to strike a downward blow on .the latch barat the upper limit of its travel. Y

7. The invention, as setfforth inclaim. 5,fwhere ina guiding wall 'for the'latch bar is carried by the door` andoverlies the cam, and said cam has a stop comprisinga part ofthe .stop means for engaging Van vedge of said wall comprising anotherpart `ofsaid .stopmeans to hold .said cam in .position where its arcuateosurfacecan be engaged by said latch bar.

8. For combinationV with a `hopper .having `a discharge opening. a pivotallymounteddoor for closing 4said opening, anda .latch .barppivotally mounted on said door to :swingparallel thereto and biased to engage a shoulderedfkeepencarriedby .saidhoppeig saidzkeeper having anlinclined striker surface -to be engaged-.by said'latch bar for displacing Vit-upwardly-when said door is swung to=closed.position-and said 'latch bar is moved upwardly fromarestpositionxtofpermit .operative Vengagement between. it and .said keeper; '.a- .dampening-element pivotally .mounted on said Ydoor. above :said Alatch ibar zito iswing in the plane thereof and .having 'fan arcuate surface -whose` center` of -.cnrvature lis spaced .horii zontally from Athe pivot axis offsaid dampening element when the same isf-to function.. as :such and whichsurfaceis adapted to be engaged by said latch bar. as it moves .over `said. striker 'surface whereby. said .dampeningselement.` and.` latch bar move .upwardly .conj ointly .mccompanied ftby .sliding and.. rolling-:contact: therebetweentand @the upward movement of the latter is correspondingly retarded.

9. For combination with a hopper having a discharge opening, a pivotally mounted door for' closing said opening, and a latch bar pivotally mounted on said door to swing parallel thereto and biased to engage a shouldered keeper carried by said hopper, said keeper having an inclined striker surface to be engaged by said latch bar for displacing it upwardly when said door is swung to closed position and said latch bar is moved upwardly from a rest position to permit operative engagement between it and said keeper; a dampening element pivotally mounted on said door above said latch bar to swing in the plane thereof and having an arcuate surface whose center of curvature is spaced horizontally from the pivot axis of said dampening element when the same is to function as such and which surface is adapted to be engaged by said latch bar as it moves over said striker surface whereby said dampening element and latch bar move upwardly conjointly accompanied by sliding and rolling contact therebetween and the upward movement of the latter is correspondingly retarded, and stop means on said door cooperating with said dampening element to position said arcuate surface in operative relation to said latch bar.

GEORGE B. DOREY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,620,097 Hindahl Mar. 8, 1927 1,790,295 Wine Jan. 27, 1931 2,030,240 Campbell Feb. 11, 1936 

